Support for timestamp sensors in time trigger automation UI

[karwosts]

Proposed change

In the automation editor for time trigger, the entity selector currently only populates with entities of domain input_datetime. The time trigger also supports entities of domain sensor, if those entities have a device_class of timestamp.

This change adds the sensors with device_class: timestamp to the entity selector.

A similar change is probably warranted in the time condition form as well. I will request approval for this code before duplicating it into the time condition as well.

Type of change

• Dependency upgrade
• Bugfix (non-breaking change which fixes an issue)
• New feature (thank you!)
• Breaking change (fix/feature causing existing functionality to break)
• Code quality improvements to existing code or addition of tests

Example configuration

Additional information

• This PR fixes or closes issue: fixes No entities with "timestamp" attribute listed when using "Time" trigger in automations #10356
• This PR is related to issue or discussion:
• Link to documentation pull request:

Checklist

• The code change is tested and works locally.
• There is no commented out code in this PR.
• Tests have been added to verify that the new code works.

If user exposed functionality or configuration variables are added/changed:

• Documentation added/updated for www.home-assistant.io

[piitaya]

It will be easier if we can use inside selector

{
  entity: {
    filter: [
      { domain: "input_datetime" },
      { domain: "sensor", device_class: "timestamp" },
    ]
  }
}

[karwosts]

I'll put a hold on this until #15302 is done.

[karwosts]

Updated to use the new entity filter options.